Cytotoxic phenylethanoid glycosides from Digitalis davisiana Heywood: Evaluation of structure activity relationships and chemotaxonomical significance of isolated compounds


KUTLUAY V. M. , ISHIUCHI K., MAKINO T., SARAÇOĞLU İ.

FITOTERAPIA, vol.135, pp.90-98, 2019 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 135
  • Publication Date: 2019
  • Doi Number: 10.1016/j.fitote.2019.04.009
  • Journal Name: FITOTERAPIA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.90-98
  • Hacettepe University Affiliated: Yes

Abstract

The phytochemical studies on the aerial parts of Digitalis davisiana Heywood led to the isolation of three undescribed phenylethanoid glycosides named as digidavisoside A (5), digidavisoside B (7), and davisoside (8), along with 9 known compounds, ferruginoside B (1), isolugrandoside (2), lugrandoside (3), maxoside (4), 3 ''''-O-methylmaxoside (6), trans-lamiuside E (9), digiciliside B (10), p-hydroxyacetophenone (11), and chrysoeriol (12). For the first time compound 11 was reported for Digitalis genus. The chemotaxonomical significance of these compounds in Plantaginaceae family was evaluated and 3'-O-glucosyl substituted phenylethanoid glycosides 4-8 and 10 were found to be chemotaxonomically important for the family. Cytotoxic activity of the aqueous fraction of the methanolic extract was also tested against HEp-2 (human larynx epidermoid carcinoma) and HepG2 (human hepatocellular carcinoma) cancer cell lines. The aqueous fraction showed stronger cytotoxicity on HEp-2 cells than on HepG2. Therefore, the cytotoxic activity of 1-4, 6, 7 and 9 were tested against HEp-2 and L929 (mouse fibroblast cell) cell lines. Other isolated compounds could not be tested due to their insufficient amount. The results were evaluated in the point of structure-activity relationships. IC50 values against HEp-2 cells were established in a range of 71.9-220 mu M. Maxoside (4), isolugrandoside (2) and lugrandoside (3) showed higher cytotoxicity against HEp.2 cell line than other isolated compounds.